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gorann

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Everything posted by gorann

  1. Thanks a lot! Yes, go for the cooled OSC especially if you do not intend to travel to sub-zero temperatures, and even then, since my DSLR (Canon 60Da) version of the Ghost was taken in January here in Sweden at -7°C. However I only got 3 hours with the Canon and I see from my notes that the moon was partly up so the comparison may not be entiery fair. But if you are into buying a new camera I think the choice is obvious.
  2. Astrodarkness is rapidly coming back to Sweden and on Saturday night it cleared and I had my third chance to try my new ASI 071 cool pro. I aimed at getting the full 7 hours of darkness but various self-inflicted mishaps put it down to 5 hours. So here is 60 x 5 min at gain 200 and offset 30, chilled to -15°C, on the Esprit 150. I am amazed how free of noise this camera is. I did take 30 darks and used them but they may not have made much of a difference. No flats since I decided that dust bunnies have not had time to infect the system yet and with the rather large image circle of the Esprit there is no signs of vignetting on this APS-C chip. Processing this faint area was quite a challenge and I appreciate comments and suggestions. While processing in PS I think I by mistake invented a new star suppression method: Inverted Hi Pass filtering. I may write a thread about that on the processing forum. For comparison I put in the image I managed to accomplish on the same object during 3 hours with my 5" ES 127ED reflector and Canon 60Da in February. Not sure if the telescope or the camera made up most of the difference, but there is quite a difference and I do not think it is not down to the small differnce in exposure time.
  3. Yes, bad choise of expression. I now we are a friendly bunch on SGL, and we are all waiting for that large-chipped mono CMOS camera that may or may never come.....
  4. PS. Before I get stamped on by the mono-people, I want to give some reasons why I suggest a cooled CMOS colour camera rather than a cooled mono camera: (1) That you do not need to buy a filter wheel and filters. (2) That you can get a larger field of view for a reasonable price. As far as I know there are no APS-C sized mono CMOS cameras (and mono CCDs of that size would cost more than your budget and are more noisy). A very popular mono CMOS camera that is about the same price (with filters and wheel) as the ASI 071 MC is the ASI 1600 MM. However, it has a considerably smaller chip. The ASI 071 chip covers a nearly 60% larger area. I just like to know that I catch as much as possible of the image produced by the telescope. PS2. I did not notice that you budget was in dollars but much of this equipment is cheaper in the US (partly due to your lower VAT) so I expect you could still get it within your budget.
  5. I agree with much that is said here and with your 3000 pound budget you can even get a nice cooled camera. I would go for the camera I just invested in - a cooled APS-C size colour CMOS camera calles ASI 071 MC-Pro. It will give you considerably better images than a DSLR (especially in warm nights) and the only small inconvenience is that you need to connect it to a laptop but the program supplied with the camera (ASICAP) is easy to use. It is very light sensitive so with the short focal length of an SW ED80 with reducer/flattener you can take short exposures (1-2 minutes) that probably need no guiding. If you add guiding to the system I suggest a simple finder guider (=using the guide scope) with an ASI120MM camera that you also connect to you laptop and the free program PHD2. Here is how it all adds up (today's FLO prices): SW 80ED = 359.- 0.85 reducer/flattener = 169.- HEQ5 Pro with belt drive = 895.- ASI 071 MC-Pro = 1479.- ASI 120MM = 126.- Total: 3028 pounds (if you take the HEQ5 without belt drive you land at 2908 pounds) For my first three years of imaging I have used Canon 60D(a) cameras (also APS-C size chips) but this autumn I started with the cooled ASI OSC and it makes quite a difference in how deep and dusty you can go in your images. Here is an example that I posted yesterday showing the same object with a DSLR and now with the cooled ASI. And I also found that you can get nice narrowband images with it even if it is a color camera.
  6. Thanks a lot! Sorry for not responding but my issues were solved in another thread. For some reason the white balance had been set to 0 (don't think it was me, maybe a cosmic ray), while I had used the default settings the earlier nights. So I am now back to default and are getting a much more homogeneous histogram. I like it better (less tweaking in initial processing) but maybe there are some advantages to having it a 0. See:
  7. Wednesday night everything was going the right way. No moon or clouds and good guiding for once (0.5" RMS) and SQM was 21.1. I was shooting off with my Esprit 150 and with my new ASI 071 Pro on the Cocoon nebula. Managed to make use of most of the dark time, which is still only about 7 hours up here. But next morning when I looked at the debayered images they were very very green. I finally managed to tweak the colour curves and get a decent histogram but it was hard work. I posted my problem here at SGL Discussions Cameras and Vlaiv finally found out what had happened. For some reason the white balance had been zeroed instead of the default (I am sure I did not do it - it just happened). In any case all the data was in there it was just a bit of a job to get a decent color balance. Here is the result. 81 x 5 min subs with this nice CMOS colour camera although it plays its ticks. Thanks again Vlaiv for explaining the strange and unexpected problems of astrophotography!
  8. Wednesday night I was imaging the Cocoon nebula with my Esprit 150 and new ASI071 pro. The object was near zenith, no visible clouds or moon, and a nice Milky Way accross the sky. My SQM showed 21.1. Even guiding was good (0.5"RMS). So everything seemed fine until next morning when I started processing the subs. The initial processing (calibration, debayer, aligning and integration) was done in PI and it was when I did the debayering that I got the chock. Everything was extremely green. I used the matrix setting given by ASI for this camera which is RGGB and I have used it before and never seen this green before. If anything I have had a blue cast, but I have only used the camera four nights. So I tried all 8 different matrix settings in PI and got various terrible colour casts and none better than with the RGGB - and it seems odd that the RGGB matrix suddenly should have changed. Wim @wimvb suggested to me that it could be Northern light that I could not see by naked eye. However, the green cast was identical in all 81 subs stretching over 6 hours, and I would expect that Northern light varies in intensity. After much tweaking with colour curves and other colour adjustments in PS I finally reached a presentable image but it was a heck of a job and I initially gave up for a while. Here is one of the green subs (only given a stretch) and also what I finally rescued after much processing. So please help! Could I have set something wrong in ASICAP. The only thing I had intentionally changed from previous sessions was to increase offset from 20 to 30. Gain was 200 and exposure 5 min but I used that before. Saturday night is supposed to be clear and now I dread what I will find on Sunday morning.
  9. gorann

    The rescued Cocoon nebula

    Yes, maybe it is. You probably started off with a zeroed white balance while ASICAP set me off with the default setting which is Blue=99, Red=60. So I got used to a slightly pink image which was easy to balance - which I do in PS after having calibrated, debayered and stacked in PI. So when I ended up with the green one I thought that something had gone terribly wrong in the debayering and I spent the whole day trying different bayer settings. If I had known what had happened I would not have worried so much..... This is what the debayered subs looked like (after a stretch), are yours as green as this?
  10. I have now checked my first sub and setting the white balance at default 60/99 (with offset at 30) gave me back the pinkish tint I used to have! Thanks again!
  11. Thanks a lot again Vlaiv! You seemed to have solved the problem. I now have it on the default 60/99 and started shooting on the Ghost nebula.
  12. Thanks Vlaiv, but now I am confused since I did not change any of those settings (and do not know how to do it). Should I find out how to change them back to the original white balance or should I continue shooting green images. I am setting up for the night right now!
  13. With the first sub tonight I will set offset to 30 and then go back to 20 for the rest. That should prove or disprove the offset hypothesis, and if it is not green at offset 30 then in was probably Aurora Borealis or something equally nasty, If they are all green again then that aurora must have parked over here or there is something seriously wrong with camera or software.
  14. Thanks a lot Vlaiv! Nothing in my hardware was changed and like before I used a Baader UV/VIS filter (the one used for Lum for mono imaging). The only software change I did was to increase offset from 20 to 30 and I hope you are right in suggesting that this may be the casue of my problem. I attach four RAW (16 bit) files as they come out of the camera (with the txt files for info). Those are the relatively comparable ones I have. It would be wonderful if you could figure something out from these! 1) From my "green session" with 3 min exposure time. Gain 200, offset 30 ASICAP_2018-09-12_22_12_40_831.FITASICAP_2018-09-12_22_12_40_831.FIT.txt 2) From my "green session" with 5 min exposure time. Gain 200, offset 30 ASICAP_2018-09-12_23_56_08_563.FITASICAP_2018-09-12_23_56_08_563.FIT.txt 3) From 1 September Lum filter with 3 min exposure. Gain 150, offset 20 ASICAP_2018-09-01_23_27_30_896.FITASICAP_2018-09-01_23_27_30_896.FIT.txt 4) From 2 September Baader Ha filter, 5 min exposure. Gain 200, offset 20 ASICAP_2018-09-02_22_50_35_428.FITASICAP_2018-09-02_22_50_35_428.FIT.txt
  15. gorann

    The insanely faint...

    The best of luck Olly & Co - look warward to a progress report with an image!
  16. gorann

    NGC6820 - finally a bit of data

    Interesting. I turned it into grayscale in PS. Will try to do it your way in PS next time Wim.
  17. Astrodarkness is getting back up here. This is the first decently large data set I got with my new ASI071mcc pro, almost 6 hours over the last two nights, but with a half moon. First night I managed to get 29 x 3 min of RGB data (gain 150 offset 20) and the second night I put on a Ha fliter and got 52 x 5 min Ha data (gain 200 offset 20). So Ha through a OSC.... yes I know it is not optimal but it has 16 megapixels and is quite sensitive with low noise and what do you do if they do not sell APS-C sized mono CMOS cameras (yet). Chip at -15°C. Stacked and calibrated in PI. Processed in PS. This is a fairly faint object so obviously more data would be nice. But I think it is a very promising camera. Comments and suggestions most welcome!
  18. gorann

    NGC6820 - finally a bit of data

    Thanks Alan! Yes, it was broad bands at least in the Ha data. Here I have "overstretched" the Ha data to emphasize the banding (First Image). Attacking it with Horizontal Banding Noise Reduction (Noel's Actions) in PS had no effect (but I know it to work fine for more narrow banding) (Second Image). However Canon Banding Reduction in PI did a very good job at removing them so as long as that works this banding is no big problem (Third Image). I know Wim @wimvbwill have a field day now when I admit that certain things work better in PI than in PS.
  19. Was the image I worked on one sub or a stacked one? If it was the stacked one then I assume you can just use it on the stacked image. Usually bands like these stay in place from sub to sub so then using it on the stack is best. It may even work well on the color data you have processed. It is a bit hidden in PI but you find it under Script -> Utilities. I used Amount = 1.0 and did not tick any of the boxes.
  20. gorann

    NGC 6823 Bicolor

    Then we are all looking forward with great excitment toward the complete version with Sii!
  21. gorann

    NGC 6823 Bicolor

    The Ha data for this image that you have recently posted on Astrobin have been really outstanding Rodd! Now there is something about your blue (Oiii) data that messes up the stars and kind of spoils it. Have you tried some really aggressive star shrinking on the Oiii data?
  22. I just learned about the PI Candon Banding Reduction a few days ago and used it succesfully in a very stretched ASI071 image. So, now I tried it (with default settings) on your red channel, and came up with this (took 10 seconds). So, you should try your free trial version!
  23. gorann

    NGC6820 - finally a bit of data

    Thanks Wim - will try and it gives me something to do on this rainy Sunday,
  24. gorann

    NGC6820 - finally a bit of data

    Thanks Olly. Yes, what is suffering in the image is colour in the smaller stars and I just need more RGB data for that. Not sure if there is much Oiii in this object that could help. In any case this is for another time with clear skies of which I have none right now. I still I think that the image shows that it is possible (but obviously not ideal) to collect Ha with these new CMOS OSCs - the 52 x 5 min of Ha is what brought out all the details in the image.
  25. gorann

    NGC6820 - finally a bit of data

    For the record. Here is the final version where I brought out as much dust as possible, suppressed red blotches in the background, and had a go at deconvolution in PI to sharpen the stars. Since there has been no clear skies I have been messing with this one for too long now.
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